Cement Industry Refractories
Rotary Cement Kiln Refractories
Based on the working condition of rotary cement kiln components, corresponding refractory materials should be chosen to meet the production requirement and obtain ideal cost performance.
- Unloading port and unloading belt: Unloading belt usually adopts 70-80% high-alumina brick, thermal shock resistant high alumina brick, spinel brick, chrome-brick. For discharge port, high alumina brick and corundum heat resistant concrete are usually used, sometimes, silicon carbide brick or castable is also a good choice.
- Sintering zone: Magnesia chrome brick, sodium polyphosphate bonded magnesia brick, alkali resistant brick and directly bonded magnesia chrome brick are often used at sintering zone. Although magnesia iron spinel brick has better kiln coating adhesion effect, it’s price is too high, so low chrome periclase spinel brick are popularly used at this part.
- Transition zone: Corundum brick, 50-80% high alumina brick, direct bonded magnesia brick, ordinary magnesia chrome brick and spinel brick.
- Cooling zone: magnesia chrome brick, high alumina brick, phosphate bonded high alumina brick, magnesia alumina spinel brick, etc.
- Decomposition zone: Clay bricks and high alumina bricks are used at the part adjacent to preheating zone. 50-60% high-alumina bricks, ordinary magnesia chrome bricks or spinel bricks are used at high abrasion and high temperature zone that connects transition zone.
- Pre-heating zone: alkali resistant insulating clay bricks.
- Preheater system: alkali resistant brick and insulating brick.
- Cooling machine system: refractory brick, lightweight castable, insulation material. Material loading part and high temperature zone can adopt general application magnesia chrome bricks, high-alumina bricks and clay bricks can be used for the medium and low temperature areas.
Main Refractories Physiochemical Index
| Item | Anti spalling high alumina brick | Periclase spinel bricks | Silicon carbide mullite bricks | Magnesia alumina spinel bricks | Magnesia iron spinel bricks | Direct bonded magnesia chrome bricks |
| A1203 | ≥70 | 6~9 | ≥63 | 1-14 | 4-6 | / |
| MgO | / | ≥78 | / | 82-81 | 87-92 | ≥80 |
| Fe2O3 | / | / | / | 0.8 | 3-5 | / |
| Cr2O3 | / | 2-4 | / | / | / | 8 |
| Refractoriness (℃) | 1780 | / | ≥1790 | / | / | / |
| 0.2MPa RUL | ≥1470 | ≥1700 | ≥1600 | ≥1700 | ≥1700 | ≥1650 |
| CCS (MPa) | ≥45 | ≥50 | ≥90 | ≥63 | 50 | ≥45 |
| Bulk density (g/cm3) | 2.5-2.6 | ≥3 | ≥2.6 | 2.85-3.0 | 2.85-3.0 | ≥2.9 |
| Thermal conductivity W/(m·k) | 1.4 | / | 2.5 | 2.8 | 2.6 | / |
New Type Dry Rotary Cement Kiln Refractories
- Preheater mechanical chained pipe: ordinary alkali resistant brick, alkali resistant castable.
- Decomposition furnace: anti-stripping high alumina brick, high alumina castable, alkali resistant brick, alkali resistant castable.
3.Tirtary air ducts: high strength alkali resistant bricks, alkali resistant castable.
- Grate cooler: high alumina castable, alkali resistant castable, stripping resistant high alumina brick, SiC composite brick, ordinary high alumina brick, chamotte brick.
- Kiln hood: anti-flaking high alumina brick, ordinary high alumina brick, high alumina castable.
- Burner: high alumina castable, corundum castable.
- Rotary kiln front hood: corundum castable, steel fiber high alumina castable, alkali resistant brick, SiC composite brick
- Lower transition zone: alkaline brick, anti-flaking high alumina brick.
- Sintering zone: basic brick, high quality phosphate high alumina brick.
- Upper transition zone: alkaline brick, anti-flaking high alumina brick.
- Decomposition zone: alkaline brick, high quality phosphate high alumina brick, anti stripping high alumina brick.
- Pre heating zone: Flaking resistant high alumina brick, phosphate high alumina brick, alkali resistant insulating brick, alkali resistant chamotte brick.
- Rear kiln inlet: high alumina castable.
